The present invention relates to a rotary or revolving connection of an electrical conductor, cable, or the like, to a more or less rigid, i.e., rather inflexible housing or casing containing for example an electric load and pertaining, therefore, to an appliance, a tool, or the like.
Revolving feed through connections are needed whenever the cable or conductor leading to an apparatus, device, etc., should not be twisted during handling. Other situations require conductors to run through a pivot joint of an apparatus, a machine, or the like, and again twisting of the conductors is to be prevented. It is apparent that those portions of the conductors or cable which are located right at the respective casing wall are endangered the most, because the conductors or cables are held at these points more or less firmly unless the points of holding yield to rotation about an axis transversely to the wall. Clearly, instruments, tooling or the like which are being moved in some fashion require most prominently that the conductors be protected against twisting.
The German printed patent application No. 2,153,418 discloses a continuous turnable conductor coupling purporting to solve the aforementioned problem. This particular coupling has an internal mechanism which permits rotation of two parts relative to each other. The conductors are inserted into the two parts and are interconnected inside of the coupling by means of U-shaped contact elements and pins or the like. Unfortunately, this coupling requires a considerable number of individual parts and is, therefore, quite expensive. Moreover, the coupling includes parts through which runs electrical current and serve also as bearings or as load supports.